Six dance lessons from Madame Lucia Varrancourt may be dangerous; at least, that is how it seems when suspicions about supposed accidental deaths lead to a dance studio.

An insurance investigator named Russ Andrews and his colleague Steve Banks are examining a religious tabernacle and its enigmatic prophet, Nostradamus, known as The Oracle. They become concerned when members of Nostradamus's fervent following start cashing in their endowment and annuity policies to donate the funds to the Nostradamus Foundation.

Following the tragedy, which took place in the darkened lobby of an office building, Andrews (James Franciscus) faces the unpleasant task of revealing Ted Harper's (Joel Crothers) death to his mother, a nightclub pianist. Kitty bitterly accuses Andrews of killing her son and won't listen to his theory that Ted may have been involved in criminal activity, since he was carrying a gun when he died. Widespread suspicion arises that Andrews may have been responsible for an innocent boy's death, and the investigator faces an uphill fight to clear himself and to unravel the truth about Ted.

In the episode titled "I Thee Kill" from *The Investigators*, Mickey Rooney guest stars as a key character. The story revolves around a struggling artist who is jilted by his wealthy fiancée, making him the prime suspect when a sniper kills her groom on their wedding day. The artist insists on joining the crowd outside the church to catch a glimpse of his former girlfriend and her new husband. Shortly after he arrives, the groom is shot, and all evidence points to the ex-boyfriend as the main suspect.

The story revolves around an aging actress who seeks compensation for the loss of her valuable art collection. Minna Carter, portrayed by Miriam Hopkins, was a renowned actress during the silent film era. She becomes indignant when investigator Russ Andrews suggests that her insurance claim may not be valid. However, as the investigating firm meets the eccentric characters working in her household, the intrigue surrounding the case deepens.

Dina Merrill is featured in "Style of Living" as a socialite who tells investigators that her husband has gotten himself deeply into debt due to gambling. She is afraid for his life, fearing that the man who holds his IOUs might kill him. The beautiful Valerie Corbin (played by Miss Merrill) informs investigators Russ Andrews and Steve Banks that her husband, Jim Corbin (Edward Binns), is heavily indebted to a gambler named Joe Vincent (James Lanphier) and that she believes his life may be in danger. Shortly after contacting Vincent, Banks is kidnapped and held captive by a pair of thugs, lending credibility to Mrs. Corbin's concerns.

A female fashion designer, portrayed by guest star Diana Lynn, reports the loss of her exclusive fall line in a fire. This prompts "The Investigators" to receive an anonymous tip, triggering an inquiry into the designer's activities. Investigator Russ Andrews encounters a frosty reception when he interviews Manon Cuchet, the dressmaker, about the circumstances surrounding the fire. It becomes evident that she is trying to protect her caretaker, Charles Victor, from scrutiny. Later, Andrews meets one of the designer's former models, Georgette, who suggests she has information that could assist his investigation. However, the lead goes cold when she fails to show up for a scheduled meeting with him.

The plot centers around an arson case in a cannery village, but the investigation is lightened by rich, down-to-earth characterizations. Notably, Robert Middleton portrays De Luca, a foreign-type character who attempts to spark a romance between Investigator Steve Banks, played by James Philbrook, and his daughter, portrayed by Judi Meredith. The lively interactions among the simple folk feel authentic, thanks in part to strong performances from Mario Alcade as a frustrated suitor and other Greek clansmen, including Vito Scotti and Nick Dennis. Interestingly, a real Greek Orthodox priest, Father Spencer Kazios, appears as himself in a scene where the fishing fleet receives a blessing.

A seemingly psychopathic killer strangles waitresses on Monday nights and leaves lipstick crosses on their foreheads. Jane Wyman plays a restaurant owner and Nancy Rennick is victim number four. “The Investigators” begin tracking down a mysterious killer who preys on waitresses, but not in time to prevent the death of another young girl employed by restaurant owner Elaine, played by guest star Jane Wyman. Russ Andrews befriends a shy young waitress, Marla Jensen (Nancy Rennick), at Elaine's, but she fails to fake him into her confidence, refuses protection, and turns up as the killer's next victim Andrews’ investigation then leads him to Walter Keeler (Peter Leeds), a fast-talking salesman who had been observed bothering Marla in the restaurant the night of her death. Keeler establishes a clear-cut alibi, however, putting a new light on the case.

A wealthy horse breeder dies in an avalanche set off by a construction company’s dynamite charges and “The Investigators” suspect that the estate owner's death was anything but accidental.

Maggie Peters finds herself romantically attracted by the insecure young heir to a factory fortune when she attempts to unravel the mysterious series of fires which break out in a New England industrial town.

Charity Kittridge reluctantly poses as a pigeon to catch a murder-for-insurance ring because she needs the money. When she rejects a strong man (Cal Bolder) as her pigeon "bridegroom," detective Steve Banks (James Philbrook) steps in to stage the fictitious union. This lays the groundwork for the murder ring to be exposed. When Charity is on the verge of being killed, co-investigator Russ Andrews prevents the plan from failing.

A man believed dead asks an insurance company to change his beneficiary. “Investigators” locks the door with an appropriately titled yarn, “The Dead End Man.” Henry Jones plays a man who gives up his hum-drum life of commuting on the 7:10 train and becomes a Bowery bum. His wife hunts him down when she gets word that he has changed beneficiaries on his insurance. Pat Carroll as Blossom is one of his six new beneficiaries.